Primary total hip arthroplasty for displaced femoral neck fracture.

Total hip arthroplasty (THA) for displaced femoral neck fracture has potential advantages over open reduction/internal fixation and hemiarthroplasty. Thirty-seven patients who underwent THA for displaced femoral neck fractures between June 1993 and June 2005 were evaluated, and the exact head/neck ratios were calculated by the prosthesis manufacturers. The major complication rate was 16.1% (6 of 37) with 5 dislocations (all with surgery prior to 2002) and one nonfatal myocardial infarction. One- and 2-year mortality was 2.7% (1 of 37) and 8.1% (3 of 37), respectively. A smaller head/neck ratio (P=.002) in patients who dislocated was observed. The optimal head/neck ratio was =/>2.13. Total hip arthroplasty for displaced femoral neck fracture allows patients to return to most preinjury activities. In order to avoid dislocation, constructs with a larger head/neck ratio should be used.